Process for selecting an order in an Item-on-Demand order selection system

ABSTRACT

An order selection process is provided for the selecting of a plurality of a predetermined item or items from a stocked picking location in an order selection system. This process includes a method for converting a computer generated order selection form (pick ticket), a method and device for reading the order selection form (pick ticket), and a method for communication with a plurality of discharge conveyors.

REFERENCE TO RELATED APPLICATIONS

This application claims one or more inventions which were disclosed inProvisional Application No. 62/409,584, filed Oct. 18, 2016, entitled“PROCESS FOR SELECTING AN ORDER IN AN ITEM-ON-DEMAND ORDER SELECTIONSYSTEM”. The benefit under 35 USC § 119(e) of the United Statesprovisional application is hereby claimed, and the aforementionedapplication is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The invention in general relates to material handling systems in thewarehousing and distribution industry and more specifically to theselection of items from a stocked location for conveyance to a packingarea for order fulfillment. The invention also relates in general to thefield of automatic order selection (goods to person) material handlingsystems and more specifically to the use of optical recognition scanningas a prime mover in the system.

Description of Related Art

Order selection is the procedure of selecting an item or itemstypically, but not limited to, less than case lot quantities from aprepared list also known as a “pick ticket” or “order selection form”.These items reside in a main warehouse or distribution center in stockedlocations and are selected for transfer to an external wholesalesupplier, retail end user, or to a retail outlet for further point ofsale distribution.

A number of systems and methods are currently employed by distributorsand order selectors to achieve the result of goods or items requested bya purchaser to be selected and brought to a packing area for preparationto ship. This includes order selection from a printed paper orderselection form (pick ticket) with human labor performing the physicaltask of locating, selecting, and movement of the item or items (goods)to a packing area for preparation of shipment. This also includes theuse of integrated warehouse management software to select items throughthe use of electro-mechanical discharging apparatus, automatic sortationsystems for routing to destination, and the use of programmed roboticequipment to replace human labor.

In almost all systems and methods, an order selection form (pick ticket)may be printed for use in quality assurance, order selection, andcustomer shipment information, if required.

Economy of labor and energy consumption to perform the tasks of orderselection is an obvious factor of profitability. Increases in speed oforder selection are desirable for the distributor/selector to be able toprocess more goods or items through an existing facility in a shorteramount of time, thereby increasing profitability.

Current and prior art does not sufficiently address the difficulties inan uncomplicated or cost efficient manner.

The most fundamental difficulties are as follows:

-   -   1. Speed of order selection for availability to the packing        area.    -   2. Item-on-demand or goods to person systems that are not        conducive to a wide variety or sizes of items to be selected by        an order selection process.    -   3. Item-on-demand or goods to person systems that are not energy        efficient.    -   4. Item-on-demand or goods to person systems that require an        overabundance of physical space to reach an acceptable level of        performance.    -   5. Item-on-demand or goods to person systems that are difficult        to implement due to major software integrations and the costs        associated with these integrations.

SUMMARY OF THE INVENTION

In summary, specifically addressing the difficulties mentionedpreviously, the invention disclosed in this application is as follows:The use of PLC controlled discharge conveyors utilizing a specificallydesigned Self Controlled Sheetfeed Optical Recognition Scanner as aprime mover discharges an item or items for conveyance to a packing areaat a very high rate of speed resulting in an increase of productivitycompared to most conventional methods and current art.

A wide variety of items of different sizes and weights may be processedwith this system. Physical detection of an individual item on conveyanceis basically the main requirement for usage in this system.

This Item-on-Demand (I.O.D.) system utilizes a start/stop/wait approachto order selection which efficiently keeps the electrical powerconsumption down to a minimal amount based on the item or items demandedwhile maintaining a very high rate of order selection speed. The use ofmodular cubicals containing small parts discharge conveyors and highdensity arrangements for package, tote, pallet and other conveyorsutilizes cubic space availability to a very high degree, utilizing thedischarge conveyors as a means of storage.

The rear loading feature of all discharge conveyors, both modular andcompacted, reduce the amount of forklift aisles and overallrestock/order selection aisles. This also results in a first in/firstout discharge of items.

The invention disclosed in this application may be utilized as anadaptive method for warehouse management systems, or order selectionsoftware by simply changing the font in the form fields of quantity andlocation to a barcode font or OCR font and utilizing a specificallydesigned Self Controlled Sheetfeed Optical Recognition Scanner as aprime mover to initiate the order selection process. This eliminates theneed for major software integration changes and/or proprietary softwaresystems for item-on-demand systems. It may operate as a standalonesystem or may be integrated into other systems for informationalpurposes.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a flowchart of system components and activity.

FIG. 2 shows a plan view of a self controlled sheetfeed optical scanner.

FIG. 3 shows an overall diagram of an order selection system.

FIG. 4 shows a side view of the main components of a self controlledsheetfeed optical scanner.

FIGS. 5a-5c show examples of a linear read by a self controlledsheetfeed optical scanner.

FIG. 6a shows a side view of a modular cleated discharge belt conveyor,without motor or takeup plate.

FIG. 6b shows a side view of a modular cleated discharge belt conveyor,with motor and takeup plate, but without limit switch or belt.

FIG. 6c shows an aisle side view of a modular cleated discharge beltconveyor.

FIG. 7 shows an end view of a modular cubical of cleated belt dischargeconveyors.

FIG. 8 shows a side view of a modular cubical of cleated belt dischargeconveyors.

FIGS. 9a-9c show a schematic representation of a trigger method fordischarge conveyors.

DETAILED DESCRIPTION OF THE INVENTION

The I.O.D. (Item-on-Demand) system as described herein and shown indiagram form in FIG. 3 is very basically an adaptive process that may beutilized with existing warehouse management systems that produce anorder selection form (pick ticket) in printed form.

The system can be used in a warehouse, shown in an example diagram ofFIG. 3. It will be understood that the drawing in FIG. 3 is a simplifieddiagram provided solely to place the invention in context, and is notintended to limit the scope of the invention. The system is usable inmany different arrangements and environments, as may be needed by theparticular application to which it is applied.

In the example of FIG. 3, a number of storage banks 303 a-303 n areshown, separated by stocking aisles 311. Each bank 303 a-303 n has aplurality of cubical discharge modules 305, each cubical dischargemodule housing a plurality of cleated discharge belt conveyor modules,which will be shown and described in detail below. The conveyor modulesof the discharge modules 305 dispense items 310 onto takeaway conveyors304 a-304 n. It will be understood that the number and arrangement oftakeaway conveyors 304 a-304 n will vary depending on the number anddesign of the storage banks 303 a-303 n.

The takeaway conveyors 304 a-304 n from each storage bank 303 a-303 nmay lead directly to a pickup or packing area 309, or they could deposititems 310 onto one or more connecting belts 308, depending on theparticular environment into which the system is installed.

Once the items 310 arrive at the pickup or packing area 308, they can becombined into larger packages or packed for shipping, as is known to theart.

The system begins by modifying the text in the form fields of quantityand location of an order selection form (pick ticket) to a standard 1Dbarcode font such as code 39 or an OCR character font. This is easilydone in most, if not all, current order selection form (pick ticket)software packages.

An order selection form (pick ticket) is then printed in paper form 301on a printer in a location near to the packaging zone of the order to beselected.

The order selection form (pick ticket) 301 is then introduced into aspecifically designed Self Controlled Sheetfeed Optical RecognitionScanner 302 by a human operator. An operator may manage more than oneSelf Controlled Sheetfeed Optical Recognition Scanner at a time.

The Self Controlled Sheetfeed Optical Recognition Scanner 302 reads thequantity and location of the item or items to be selected by cycling theorder selection form (pick ticket) 301 by means of a friction driveroller through an area in which resides a fixed but adjustable opticalrecognition scanner, as will be described below. The scanner reads thecodes or characters and transmits ASCII information to a programmablelogic controller (PLC) 307 residing within the Self Controlled SheetfeedOptical Recognition Scanner 302 assembly.

The PLC 307 then performs two major functions within milliseconds ofeach other. It first stops the friction drive roller motor of the SelfControlled Sheetfeed Optical Recognition Scanner 302 for the length oftime the discharge conveyors are expected to be in discharging mode, andsecondly, it sends the appropriate information of quantity and locationto a secondary “slave” PLC that resides in a control panel mountedwithin the discharge conveyor cubical or to a package/tote dischargeconveyor control panel in the cubical discharge modules 305 of thestorage banks 303 a-303 n.

The stoppage of the friction drive roller motor of the Self ControlledSheetfeed Optical Recognition Scanner is important to insure that morethan one discharge conveyor motor or the Self Controlled SheetfeedOptical Recognition Scanner drive motor is not operating at the sametime. By limiting the operation of multiple motors, this systemaddresses the concern of energy efficiency.

In an example of efficiency or minimal power consumption, a typicalsmall parts discharge conveyor may use a low voltage (i.e. 12V) DC gearmotor drawing less than 3 amps or 36 watts. A typical small partsconveyor may be set to discharge an item or part every 750 millisecondsor ¾ of a second. This would put the average rate of speed of the SelfControlled Sheetfeed Optical Recognition Scanner at 80 items per minutedischarged from a discharge conveyor averaging 750 milliseconds perdischarge. Multiplied by 60, that puts the operating range of a singleSelf Controlled Sheetfeed Optical Recognition Scanner at 60×80=4,800items per hour. This is done with not more than one motor drawing lessthan 3 amps at 12 volts DC (36 watts) at a time.

The above example is a typical small parts discharge conveyor. Otherdischarge conveyors may be larger and require longer run times (reducingselective time rates) and more amperage consumption, but the concept isclearly the same. An example of a larger discharge conveyor would be astandard line shaft roller conveyor operating at 65 feet per minute (or923 milliseconds per foot). Using a package or tote size of 2 feet inlength the discharge time would be 1.846 seconds per item. 60 secondsdivided by 1.846=32.5 items discharged per minute or 1,950 packages ortotes per hour. In a typical warehouse or distribution application(e-commerce for example) a 2 foot long package is reaching the high endof typically shipped items. For larger items such as the package or toteapplication a 3 phase motor in the range of 460 volts could be used forthe application. On a standard ¾ horsepower 460V 3 phase motor thecurrent draw would be near the 1.4 amp range (or 644 watts).

The above examples are randomly picked sizes and possibilities of thesystem to address the issue of energy efficiency and may not apply inall scenarios. The type of discharge system will be product oriented andcustomer driven, designed specifically for each application based onspeed of discharge requirements, available electrical power supply, andproduct weight.

If the items 310 requested are small parts, they may be discharged ontoa conventional troughed slider bed belt conveyor 308 for conveyance tothe appropriate packaging zone 309 or discharged to a chute or tiltedtray or pan arrangement to be prepared for shipment or cycled to thenext appropriate zone for combination with an item or items selected anddelivered to that zone in the case of multiple zone orders.

If the items requested are boxed (package) or totes, or pallets, thenstandard conveyor appropriate for the item may be utilized to convey toa packaging or shipping area where applicable. Standard sortationmethods including, but not limited to, barcode sortation may beutilized.

The Self Controlled Sheetfeed Optical Recognition Scanner 302 thenrestarts the drive motor and the cycle begins again until all parametersets on the existing page are read, and all other pages in the SelfControlled Sheetfeed Optical Recognition Scanner assembly have beenprocessed.

Operation of System Components

FIG. 1 shows a flowchart of the operation of the system of theinvention.

-   Step 101: The form fields of item quantity and location on the order    selection form (pick ticket) must be modified to an optically    recognized font for use in the specifically designed Self Controlled    Sheetfeed Optical Recognition Scanner. These fonts may be a 1D    linear barcode font or an OCR readable character font. This is done    primarily in the settings of fonts in the applicable program used to    generate the order selection form (pick ticket).-   Step 102: An order for selection is placed with the    distributor/wholesaler, etc. who utilizes the Item-on-demand (I.O.D)    system.-   Step 103: An order selection form (pick ticket) is printed in a    location of close proximity to the packing area where the discharged    items are expected to arrive. The specifically designed Self    Controlled Sheetfeed Optical Recognition Scanner is also located in    close proximity to the pick ticket printer. This enables the pick    ticket to be conveniently added to the physical item or items as    they are prepared for packaging.-   Step 104: The specifically designed Self Controlled Sheetfeed    Optical Recognition Scanner operator feeds the pick ticket/s into    the specifically designed Self Controlled Sheetfeed Optical    Recognition Scanner face up in preparation for beginning the cycle    of order selection/discharge.-   Step 105: The Initiate (Start) button is pressed and the friction    drive roller motor engages momentarily.-   Step 106: The friction drive roller makes contact with the order    selection form (pick ticket) and drives the form from the holding    area in the infeed section to the read area in the discharge    section. A paper photoelectric proximity sensor reads that there is    a form present and continues supplying power to the friction drive    roller motor via a relay in conjunction with the master PLC ladder    logic.-   Step 107: The optical recognition scanner in the read area then    reads the first set of quantity and location as two separate    instructions.-   Step 108: The scanner then sends the information as ASCII    information to the specifically designed Self Controlled Sheetfeed    Optical Recognition Scanner Master PLC through a com port on the    master PLC located in the specifically designed Self Controlled    Sheetfeed Optical Recognition Scanner assembly.-   Step 109: The master PLC receives the information from the scanner    and reacts to the information by executing commands based on the    ASCII information it has received.-   Step 110: The master PLC program executes its ladder logic program    based on the “equal to” or “not equal to” information received from    the scanner.-   Step 110 a: One of the initial main functions of the master PLC    ladder logic program is to disengage or “stop” the friction drive    roller motor electrically for the expected duration of the item or    items to be discharged (selected) from the discharge conveyors. This    insures that the scanner will not read another set of parameters    from the order selection form and engage another discharge conveyor.    This is done to conserve available electrical power supplies and    usage.-   Step 110 b: Another initial main function of the master PLC ladder    logic program is to send information via hardwire or wireless    communication through a com port to the slave PLC which resides in a    discharge conveyor control panel. The information sent is specific    to the location relays programmed into the slave PLC ladder logic    program. There may be many multiples of discharge conveyor control    panels with slave PLC's residing in the control panels.-   Step 111: The slave PLC ladder logic program reacts to the    information received from the master PLC.-   Step 112: The slave PLC ladder logic program contains the    information for the control relay triggers of the discharge    conveyors.-   Step 112 a: The slave PLC executes a trigger signal to the    appropriate discharge conveyor for a specified length of time based    on the quantity of an item or items to be discharged. The speed of    the discharge conveyors and the length (travel distance) of items to    be discharged are known entities and easily programmed to suit    application. Differences in electric motor performances are easily    compensated for in this programming.-   Step 113: The slave PLC completes it's cycle and awaits instruction    from the master PLC.-   Step 113 a: At this point, the item or items are already discharged    from the discharge conveyor and available for conveyance to the    packing area.-   Step 114: The discharge conveyor is stopped by means of an integral    signal switch either mechanical/electrical in the case of cleated    belt discharge conveyors or photoelectric/proximity sensors in the    case of package, tote, pallet or chain conveyor discharge conveyors.-   Step 115: At this point, the expected duration of discharge has    elapsed and the timers programmed into the ladder logic of the    master PLC allow the friction drive roller motor to begin the cycle    again, driving the next set of parameters on the order selection    form into the scan/read area in the specifically designed Self    Controlled Sheetfeed Optical Recognition Scanner.-   Step 115 a: The master PLC reads the next set of parameters and    repeats the cycle as per starting point of “107” in this flow chart.-   Step 116: The item or items discharged from the discharge conveyors    are conveyed by means of standard conveyance appropriate to the    discharge conveyors and products stored on the discharge conveyors.    In the case of small parts, items may be conveyed to or directly    delivered to a tilted pan, tray, or chute system designed for the    specific application in the appropriate packing area. In the case of    package, tote, or pallet conveyor, standard methods of stops,    traffic cops metering belts, and sortation may be used for    conveyance to the appropriate packing area. In the case of chain    conveyor, appropriate transfers, pick ups and releases may be    utilized for conveyance to the appropriate packing area. All methods    of conveyance to the appropriate packing area are subject to the    properties of the item or items to be conveyed and existing standard    methods have been proven reliable and efficient in the material    handling industry.-   Step 116 a. After standard conveyance from the discharge conveyors    the item or items arrive in the predetermined packing area.-   Step 116 b: If the order is completed in this area (no further    selections), the order is packed and sent to the shipping area via    convenient means based on throughput, size, and other shipping    considerations. This may mean standard conveyance, the use of    multiple loaded totes, and/or palletization.-   Step 116 c: If the order is not complete, then the product is cycled    to the next appropriate zone/s for completion of order. Again, the    nature and properties of the product determine the method of    conveyance to the next appropriate zone.

Self-Controlled Sheetfeed Optical Scanner

FIG. 2 shows a plan view of a Self-Controlled Sheetfeed Optical Scannerof the system of the invention, and FIG. 4 shows a side view of the maincomponents of the Self-Controlled Sheetfeed Optical Scanner of theinvention.

Item 201 is a motor, preferably a low voltage, low amperage DC gearedmotor capable of at least 40 RPM, continuous duty, and able to drive thefriction roller 218 suitable for cycling a sheet from the infeed section203 into the read area 216 of the scanner. The paper infeed area 203 issupplied with adjustment holes for paper alignment.

An adjustable paper width guide 202 is provided in the infeed section203 for alignment purposes of the order selection form as it enters theinput side 220 of the infeed section 203. The infeed section 203 andguide 202 may be metal, plastic, or chemical composite in construction.A hinged location and portion 204 of the paper infeed area 203 istensioned to provide introduction of the order selection form to thefriction drive roller 218, which is an adjustable roller of metal,plastic, or chemical composite material with an attached sleeve offriction enhancing material such as latex, rubber, urethane, or othersuitable chemical composite material. The roller 218 engages an orderselection form and drives it through to the scanner read area 216. Aninfeed stop 408 can be provided to hold order selection form(s) in theinfeed area 203 until they engage roller 218 and are moved on into theread area 216.

Relay 205 controls the power feed to the friction drive roller motor201. Spring tensioned lever arm 213 is used for releasing an orderselection form from friction drive roller 218 and engaging tensionbetween the order selection form and drive roller 218.

When the drive roller 218 moves a form into the read area 216, it isread by Optical recognition scanner 215. The scanner 215 is of a typecapable of reading the optical recognition indicia on the order form ofthe types which were chosen to be used in the system, as will beexplained below.

Primary photoelectric/proximity sensor 217 senses sheet activity in theread area 216 to allow friction drive motor 218 to run if a page is inthe reading area 216. Secondary photoelectric/proximity sensor 214senses a page at the discharge end 221 of the read area 216, which givesadditional control for multiple sheet feeds.

An Initiate (start) button 219 is provided to momentarily cycle themotor 201 to introduce the order selection form into the read area 216where the primary photoelectric/proximity sensor 217 picks up thecontact and supplies power to the friction drive roller motor 201,possibly via a low voltage relay.

Power supply for the scanner is provided by the main power feed 206,which is typically at 110 VAC, through fuse 208. This supplies a powersupply 209 for low voltage circuit which provides power for frictiondrive roller motor 201 and photoelectric/proximity sensors 214 and 217.The power supply 209 is preferably protected by a fuse 208. The othercomponents of the scanner can be powered by power supply 209, or, asshown in the figure, by separate power supplies 210 for the MasterProgrammable Logic Controller (PLC) 212 and 211 for the scannercircuitry.

FIGS. 5a-5c show three examples of a linear scan read on a typical orderselection form or pick ticket 501, as the form 501 passes through thescanner in the direction noted by arrow 510.

The blocks 502 on form 501 which are marked with “X” are opticalrecognition form fields, and these may be of any sort known to the art,for example bar codes (linear or two-dimensional), target codes, oroptical character recognition (OCR) areas for printed or handwrittenindicia. The line 503 marked “SR” shows the lineal scan read area. Theangle and height of read is adjustable on the scanner in thespecifically designed Self Controlled Sheetfeed Optical RecognitionScanner assembly. Variations of font size, length of item location, andform field dimensions will determine the placement of the scan areareader.

Cleated Discharge Belt Conveyor Module

FIGS. 6a-6c show various views of a Cleated Discharge Belt ConveyorModule 600 of the system of the invention. FIGS. 6a and 6b show the sameview with the motor 608 and takeup plate 609 removed in FIG. 6a , andthe limit switch 605 and belt 604 not shown in FIG. 6b . FIG. 6c showsan aisle side view of the side plate 601, motor 608 and dischargeconveyor module plug 606.

A flexible belt 604 moves items or products from a load end of themodule 600 to a discharge end. The belt 604 is preferably, as shown thefigures, a cleated belt having cleats 610 spaced along its length, isusually made of limited stretch material such as polypropylene or canvasweave with synthetic or natural laminations. It is designed to provideequal lengths between cleats 610 for product orientation. It istypically spliced together using a metal hook and pin arrangement butmay also be spliced using chemical bonding or heat bonding materials.

A limit switch 605 provides an indication of the position of the belt604 by detecting the presence of the cleats 610 or items on the belt.The limit switch 605 could be implemented as a physical switch as shownin FIG. 6a which contacts the cleats 610, or a photoelectric sensordetecting an interruption of a light beam by an item or cleat 610, or amagnetic reed switch or Hall-effect sensor operated by magnets on thecleats 610, or an ultrasonic proximity detector, or other sensors knownto the art. An explanation of operation of the limit switch 605 in theoperation of the system is provided below with respect to the operatingstates shown in FIGS. 9a -9 c.

Two side plates 601 form the vertical structural members of the cleatedbelt conveyor module 600. These may be of varying lengths and heightsappropriately designed for specific product requirements. The horizontalstructural member 603 referred to as a “slider bed” extends between theside plates 601. This structural member 603 supports the belt 604 as itis pulled to the discharge end of the conveyor 600. It also supports theweight of the product on the belt 604, reducing the amount of energy tomove the product to the amount of sliding frictional force to overcome.Side plates 601 and structural member 603 may be manufactured fromsteel, alloy materials, plastic, or chemical composite materials.

Motor 608 is preferably a low voltage, low amperage DC motor sized asper application requirements. The motor 608 is fixed to the side plates601. Main drive roller 602 is fixed to the drive motor 608 shaft and isutilized to create the pulling force on the belt 604. Take up pulley607, mounted on take up plates 609, is adjustable to take the slack outof the belt. The main drive roller 602, take up pulley 607 and take upplate 609 can be manufactured from steel, alloy materials, plastic, orchemical composite materials.

Modular discharge conveyor module connector 606 connects the triggerfeed, ground, and constant voltage feed of the discharge conveyor module600 to a matching connector 809 on the cubical discharge module 702, asshown and discussed below in connection with FIGS. 7 and 8.

FIG. 7 shows the high density capabilities of the discharge conveyormodules 600 used in a cubical discharge module 702, shown from an end.FIG. 8 shows a side detail view of a portion of two cubical dischargemodules 702 with six discharge conveyor modules 600. The structuralsupport 703 for the cubical discharge module 702 is typically steel,such as pallet racking or a specifically engineered structure to suitapplication purposes.

The cubical discharge modules 702 may be designed using steel, alloymaterials, plastic, or chemical composite materials as per theapplication requirement. Each cubical discharge module 702 will have acontrol panel 802 which houses the slave PLC and control relays for thedischarge conveyor modules 600 in the cubical discharge module 702. In avery simple manner, an individual discharge conveyor module 600 can haveits connector 606 disengaged from the matching connector 809 on thecubical discharge module 702 and removed for restocking of productbetween the cleats 610, then replaced.

A plurality of discharge conveyor modules 600 as described above aremounted in a support structure 805 in the form of a modular cubicalframework which supports the discharge conveyor modules 600 and residesin the structural framework of a pallet rack or design engineeredsteelwork 803. Size and characteristics of the framewark are designed asper application.

Each cubical discharge module 702 will have a control panel 802 whichhouses the slave PLC and control relays for the discharge conveyormodules 600 in the cubical discharge module 702.

A takeaway conveyance 804, shown in FIG. 8 as a typical trough conveyor,moves items or products dispensed to a packing area. Application willdetermine size, quantity and type of conveyance 804.

Trigger Method for Operation of Discharge Conveyors

FIGS. 9a-9c show the three basic states of the discharge conveyor module600 switch circuit. In each figure, power is supplied through a powerinput 901 through a limit switch 605. The output 902 of limit switch 605is coupled to the motor or relay lead 905 which powers belt motor 608and relay 903. It will be understood that the motor or relay lead 905may power a motor 608 and relay 903 in parallel as shown in the figure,or it may power only one of the discharge motor 608 or relay 903 whichcan then power a larger type of discharge conveyor such as package,pallet, chain, etc. . . . . In another embodiment the power from themotor or relay lead 905 may be arranged to power the motor 608 and relay903 sequentially to reduce available power requirements.

The limit switch 605 is operated by the belt cleats 610 on the belt 604or, alternatively, by the presence of an item on the belt 604, arrangedso that the switch 605 is open (does not supply power to the motor orrelay lead 905 through switch output 902) when a cleat 610 or item ispresent in proximity to the switch 605, and the switch 605 is closed(supplies power to the motor or relay lead 905 through the switch output902) when the switch 605 is in between cleats 610 or items.

A PLC trigger line 906 leading from the slave PLC in parallel with thelimit switch 605 circuit, allows the PLC to close a switch 907 and powerthe motor 608 or relay 903, independent of the position of the limitswitch 605.

The three basic states are as follows:

-   READY STATE: As shown in FIG. 9a , in this state the conveyor module    600 is inactive. The proximity of a cleat 610 or item holds the    limit switch 605 in the open position, so that switch output 902 is    unpowered. The PLC trigger line 906 is also unpowered, so that PLC    trigger switch 907 is also open. With both switches 605 and 907    open, there is no power on the motor or relay lead 905 and motor 608    and relay 903 are unpowered, so that the belt 604 is stationary.-   TRIGGER STATE: As shown in FIG. 9b , in the trigger state the PLC    puts a trigger signal on the PLC trigger line 906, so that PLC    trigger switch 907 closes. This supplies power to the motor or relay    lead 905, which powers motor 608 and relay 903. The motor 608 causes    belt 604 to move. The trigger signal needs to remain on the PLC    trigger line 906 only long enough to move the belt 604 enough to    move the cleat 610 or item away from the limit switch 605, so that    limit switch 605 changes to the closed position, supplying power to    switch output 902. This puts the system in operation state, see FIG.    9c , below.-   OPERATION STATE: As shown in FIG. 9c , once the cleat 610 has moved    away from the limit switch 605, the switch 605 is in the closed    position, supplying power through the switch output 902 to the motor    or relay lead 905, which keeps the motor 608 powered, even though    trigger switch 907 has opened. The belt 604 continues to move until    a cleat 610 or item arrives in proximity to the limit switch 605,    which causes the switch 605 to open, and the system returns to the    ready state, FIG. 9a , above.

As explained above, this allows the PLC to dispense a single item on thebelt by momentarily triggering switch 907 just long enough for thesystem to enter operational state. The belt 604 moves just far enough tomove the next cleat 610 or item to the limit switch 605, then stops. Ifit is desired to dispense more than one item, the PLC can simply repeatthe process multiple times, triggering the system from ready state totrigger state to operational state and back to ready state as many timesas needed.

Alternatively, more than one item can be dispensed in a continuousmanner without starting and stopping the belt by prolonging the triggerstate of FIG. 9b . The item quantity would be determined by the lengthof time the signal on the PLC trigger line 906 holds trigger switch 907closed.

This can be accomplished by calculation, if the belt speed and thelength of the product or distance between cleats are known values. Insuch an embodiment, the PLC would determine how long the belt would haveto move until the belt length has passed the limit switch 605, then holdthe trigger switch 907 closed for that length of time. The triggerswitch 907 would then be opened, and the belt would continue to move inoperational state until the next cleat or item causes the system to goback into ready state, as described above. The calculation of therequired length of time the trigger signal needs to be held for a givenquantity can be done as part of the determining process done by the PLC.Alternatively, a predetermined length of time can be pre-calculated andprogrammed into the PLC for each of the known quantities and locationsof the individual discharge conveyor modules, so that the determiningprocess is performed by using the quantity to look up the predeterminedtime.

For example, suppose it takes 750 milliseconds for the belt to movesufficiently to discharge a single item (or for the cleat arrangement tomove one cleat), and suppose it takes at least 150 milliseconds for thebelt to move enough to allow the system to switch from trigger state tooperational state (that is, to move the belt enough so that the limitswitch 605 takes over powering the motor 608 from the trigger switch907). To dispense one item, the trigger signal would need to be at least150 milliseconds duration—after that, the normal operation of the systemwill return to ready state after the single item is dispensed. Todispense two items, the trigger signal would need to be 150 millisecondsto start the belt, plus 600 milliseconds for remaining movement of thefirst item (at this time the system would normally return to ready statebecause a cleat or item opens the limit switch, but because the triggersignal is still closing the trigger switch the belt keeps on moving),plus 150 milliseconds more to keep the belt moving long enough to closethe limit switch and start the operational state again to dispense thesecond package, for a total of 900 millisecond trigger signal duration.Further quantities utilize the same calculations for the trigger signal.

Alternatively, the PLC could have an input monitoring the state of thelimit switch 605, so that if it were desired to dispense more than oneitem the PLC would raise a trigger signal to close the trigger switch907 and cause the system to enter operational state, and then hold thetrigger signal until the limit switch 605 has closed one fewer time thanthe number of items to be dispensed. Then the trigger signal can belifted, and the system will remain in operational state long enough todispense one more item, then re-enter ready state as normal.

Accordingly, it is to be understood that the embodiments of theinvention herein described are merely illustrative of the application ofthe principles of the invention. Reference herein to details of theillustrated embodiments is not intended to limit the scope of theclaims, which themselves recite those features regarded as essential tothe invention.

What is claimed is:
 1. An item-on-demand dispensing system, comprising:a plurality of storage banks for storing and dispensing items, eachstorage bank comprising: a plurality of cubical discharge modules, eachcubical discharge module comprising: a plurality of discharge conveyormodules for dispensing items, each discharge conveyor module having aroller conveyor or flexible belt conveyor for storing and moving aplurality of items between a load end and a discharge end of theconveyor, and a motor for driving the conveyor; a plurality of takeawayconveyors located along a length of at least one of the storage banks,adjacent to the discharge end of the plurality of discharge conveyors,each of the plurality of takeaway conveyors having a length and adischarge end, such that items discharged from the discharge end of thedischarge conveyors are deposited onto the length of the takeawayconveyors; a packing area for receiving items from the plurality oftakeaway conveyors; at least one optical scanner for scanning orderselection forms specifying items to be dispensed; and a controllercoupled to the plurality of storage banks, the plurality of takeawayconveyors, and the optical scanner; the controller being programmed suchthat when an order selection form specifying an item to be dispensed isscanned by the at least one optical scanner, a discharge conveyor modulecontaining the item is operated to dispense the item from the dischargeend of the discharge conveyor module onto a takeaway conveyor, thetakeaway conveyor conveys the item to the discharge end of the takeawayconveyor, and the item specified on the order is dispensed into thepacking area.
 2. The system of claim 1, in which the flexible beltconveyor of the discharge conveyors are cleated.
 3. The system of claim1, further comprising a printer in a location near to the packing areafor printing order selection forms for reading by the optical scanner.4. The system of claim 1, in which each of the plurality of storagebanks further comprises at least one slave controller coupled to thedischarge conveyor modules in the cubical discharge module, and thecontroller is coupled to the storage banks through the at least oneslave controller of the storage bank.
 5. The system of claim 4, in whichthe at least one slave controller comprises a slave controller in eachof the cubical discharge modules of the storage bank.
 6. Aself-controlled sheetfeed optical scanner reading an order selectionform with order information in an item-on-demand dispensing system,comprising: an infeed section for holding a stack of order selectionforms, comprising: an input section; a guide for centering paper on theinput section; a hinged portion on a lower end of the input section; aninfeed stop for holding the stack of order selection forms in the infeedsection; a drive roller adjacent to the hinged portion of the infeedsection, the hinged portion of the infeed section being tensioned tobring an uppermost order selection form from a stack held on the infeedsection into contact with the drive roller; a read area adjacent to thedriver roller, comprising: a primary proximity sensor adjacent to thedrive roller for sensing the presence of an order selection formentering the read area; and an optical scanner located above the readarea, optically scanning a linear area across a width of the read area,imaging optical recognition indicia on the order selection form as theorder selection form passes through the read area; a motor coupled tothe drive roller, for rotation of the drive roller such that actuationof the motor rotates the drive roller, moving the uppermost orderselection form from the infeed section into the read area; and acontroller coupled to the optical scanner, the primary proximity sensorand the motor, having an input for receiving an instruction to initiatea read operation and an output for transmitting scanned orderinformation derived from the optical recognition indicia on the orderform in the read area to a system controller of the item-on-demanddispensing system; the controller being programmed such that: when thecontroller receives an instruction to initiate a read operation, thecontroller activates the drive roller to feed the uppermost orderselection form from the hinged portion of the input section into theread area; the presence of the order selection form is sensed by theprimary proximity sensor; the optical scanner is activated to scan thelinear area across the width of the read area, imaging opticalrecognition indicia on the order selection form as the order selectionform passes through the read area and sending imaging data to thecontroller; the controller accepts the imaging data from the opticalscanner, processing the imaging data to derive a quantity and a locationfor each item on the order selection form in the read area which is tobe dispensed by the item-on-demand dispensing system; when all ofoptical recognition indicia on the order selection form in the read areahave been imaged and the imaging data has been processed by thecontroller, the controller sends the quantity and location for each itemon the order selection form in the read area which is to be dispensed bythe item-on-demand dispensing system through the output to the systemcontroller of the item-on-demand dispensing system; wherein the drivemotor of the sheetfeed optical scanner is not activated while theitem-on-demand dispensing system is dispensing items from the orderselection form and when the primary proximity sensor senses that an endof the order selection form has passed into the read area, thecontroller stops a drive motor of the sheetfeed optical scanner.
 7. Thesheetfeed optical scanner of claim 6, further comprising a secondaryproximity sensor adjacent to an exit end of the read area, coupled tothe controller, for sensing the presence of an order selection formdischarging from the read area.
 8. The sheetfeed optical scanner ofclaim 6, in which the optical recognition indicia are selected from agroup consisting of: machine-readable codes and optical characterrecognized text.
 9. The sheetfeed optical scanner of claim 6, in whichthe controller further comprises an input for suspending read operationwhile the item-on-demand dispensing system is dispensing an order, andthe controller is further programmed such that the drive motor is onlyactivated when there is no indication on the input for suspending readoperation.
 10. The sheetfeed optical scanner of claim 6, in which thecontroller is further programmed to start a timer upon stopping thedrive motor, and does not activate the drive motor again until the timerhas indicated the passage of a time sufficient for the item-on-demanddispensing system to dispense the items on the order selection form. 11.The sheetfeed optical scanner of claim 6, in which the guide of theinput section is adjustable to accommodate order selection forms ofdiffering widths.
 12. The sheetfeed optical scanner of claim 6, furthercomprising a spring tensioned lever arm coupled to the hinged area ofthe infeed section, for releasing and engaging tension between theuppermost order selection form and the drive roller.
 13. The sheetfeedoptical scanner of claim 6, further comprising an initiate buttoncoupled to the input for receiving an instruction to initiate a readoperation of the controller, such that operating the initiation buttonsends an instruction to initiate a read operation to the controller. 14.A method of operating an item-on-demand dispensing system comprising aplurality of storage banks for storing and dispensing items, eachstorage bank comprising a plurality of cubical discharge modules, eachcubical discharge module comprising a plurality of discharge rollerconveyors or discharge belt conveyors for dispensing items, eachdischarge conveyor having rollers or a flexible belt for storing andmoving a plurality of items between a load end and a discharge end ofthe rollers or flexible belt, and a motor for driving the rollers or theflexible belt; a plurality of takeaway conveyors located along a lengthof at least one of the storage banks, adjacent to the discharge end ofthe plurality of discharge conveyors, each of the plurality of takeawayconveyors having a length and a discharge end, such that itemsdischarged from the discharge end of the discharge conveyors aredeposited onto the length of the takeaway conveyors; a packing area forreceiving items from the plurality of takeaway conveyors; at least oneoptical scanner for scanning order selection forms specifying items tobe dispensed; and a controller coupled to the plurality of storagebanks, the plurality of takeaway conveyors, and the optical scanner; themethod comprising the steps of: a) receiving an order specifying atleast one item for dispensing by the item-on-demand dispensing system;b) printing an order selection form bearing optical recognition indiciaspecifying a quantity and a location for at least one item on the orderwhich is to be dispensed by the item-on-demand dispensing system; c)optically scanning the order selection form by the at least one opticalscanner; d) the optical scanner sending the quantity and location forthe at least one item on the order selection form which is to bedispensed by the item-on-demand dispensing system to the systemcontroller of the item-on-demand dispensing system; e) the systemcontroller operating a discharge conveyor module containing the at leastone item to dispense the at least one item from the discharge end of thedischarge conveyor module onto a takeaway conveyor; f) the takeawayconveyor conveying the at least one item to the discharge end of thetakeaway conveyor, and dispensing the at least one item into the packingarea; g) if there are more items on the order to be dispensed by theitem-on-demand dispensing system, the system controller repeating steps(e) and (f) until all items on the order have been dispensed.
 15. Themethod of claim 14, in which step (c) of optically scanning the orderselection form is performed by a self-controlled sheetfeed opticalscanner comprising an infeed section for holding a stack of orderselection forms, comprising an input section; a guide for centeringpaper on the input section; a hinged portion on a lower end of the inputsection; an infeed stop for holding the stack of order selection formsin the infeed section; a drive roller adjacent to the hinged portion ofthe infeed section, the hinged portion of the infeed section beingtensioned to bring an uppermost order selection form from a stack heldon the infeed section into contact with the drive roller; a read areaadjacent to the driver roller, comprising a primary proximity sensoradjacent to the drive roller for sensing the presence of an orderselection form entering the read area; and an optical scanner locatedabove the read area, optically scanning a linear area across a width ofthe read area, imaging optical recognition indicia on the orderselection form as the order selection form passes through the read area;a motor coupled to the drive roller, for rotation of the drive rollersuch that actuation of the motor rotates the drive roller, moving theuppermost order selection form from the infeed section into the readarea; and a controller coupled to the optical scanner, the primaryproximity sensor and the motor, having an input for receiving aninstruction to initiate a read operation and an output for transmittingscanned order information derived from the optical recognition indiciaon the order form in the read area to a system controller of theitem-on-demand dispensing system; and the method of step (c) comprisesthe steps of: the controller receiving an instruction to initiate a readoperation; the controller activating the drive roller to feed theuppermost order selection form from the hinged portion of the inputsection into the read area; the primary proximity sensor sensing thepresence of the order selection form; activating the optical scanner toscan the linear area across the width of the read area; the opticalscanner imaging optical recognition indicia on the order selection formas the order selection form passes through the read area and sendingimaging data to the controller; the controller accepting the imagingdata from the optical scanner; the controller processing the imagingdata to derive a quantity and a location for each item on the orderselection form in the read area; when all of optical recognition indiciaon the order selection form in the read area have been imaged and theimaging data has been processed by the controller, the controllersending the quantity and location for each item on the order selectionform in the read area which is to be dispensed by the item-on-demanddispensing system through the output to the system controller of theitem-on-demand dispensing system.
 16. The method of claim 15, in whichthe controller of the self-controlled sheetfeed optical scanner furthercomprises an input for suspending read operation while theitem-on-demand dispensing system is dispensing an order, and methodfurther comprises the step of the system controller sending anindication to the input for suspending read operations during theexecution of steps (e) through (g), such that the drive motor of theself-controlled sheetfeed optical scanner will not be activated whilethe item-on-demand dispensing system is dispensing items from an orderselection sheet.
 17. The method of claim 14, in which the item-on-demanddispensing system further comprises at least one connecting roller orbelt conveyor having a length located adjacent to the discharge ends ofthe plurality of takeaway conveyors, a discharge end adjacent to thepacking area, and a motor for driving the connecting roller or beltconveyor, and the method further comprises the system controlleroperating the motor of the connecting roller or belt conveyor such thatitems discharged from the discharge end of the plurality of takeawayconveyors are deposited onto the length of the connecting roller or beltconveyor and conveyed to the packing area.
 18. The method of claim 14,in which each of the plurality of storage banks further comprises atleast one slave controller coupled to the discharge conveyor modules inthe cubical discharge module, and the controller is coupled to thestorage banks through the at least one slave controller of the storagebank, and step (e) of the system controller operating the dischargeconveyor module is performed by the system controller sending commandsto the at least one slave controller.
 19. The method of claim 18, inwhich the at least one slave controller comprises a slave controller ineach of the cubical discharge modules of the storage bank.
 20. Themethod of claim 14, in which the optical recognition indicia is selectedfrom a group consisting of: machine-readable codes and optical characterrecognized text.